I agree re: marketing -- something I had easily fell for. One of the authors has moved onto writing another Haskell book (a "work of art" apparently), but this time my interest, for an intermediate level book, is elsewhere: https://intermediatehaskell.com/ (which would be more informative--thus pedagogically sound--than a work of art).

Lesson learned: don't fall for the marketing of art.

Generally the best way to learn is by actually doing projects: http://www.haskellforall.com/2017/10/advice-for-haskell-begi...